The invention relates to a container for liquefied gas.
It is known for containers for liquefied gas, such as Liquefied Natural Gas (LNG), which is stored and transported at a temperature of -162.degree. C, to be made of a material which is ductile at cryogenic temperatures, e.g. nickel steel or aluminum, and for a heat insulating layer to be provided on the outside thereof. In the case of land tanks it is also necessary for safety reasons to provide an external self-supporting protecting container of reinforced or prestressed concrete. In the case of floating containers a special floating body, for example a ship's hull made of steel, is necessary. Between the container and the floating body there must be provided a second barrier, for example a layer of plywood. This layer has the purpose of preventing the cold liquid from coming into direct contact with the floating body in the event of a leak in the container, which would lead to immediate embrittlement of the material to the point of fracture, since for reasons of cost the floating body cannot also be made of a material which is ductile at cryogenic temperatures.
It is also known for a container for liquified gas to be made self-supporting of steel or aluminum which is ductile at cryogenic temperatures with an internal heat insulating layer. For safety, the same measures are necessary here for land tanks and floating tanks as in the case of containers with external heat insulation.
Finally, there are also known containers or reinforced concrete with an internal, non-load-bearing sealing layer of steel or aluminum which is ductile at cryogenic temperatures and with an external heat insulating layer. In this design, both the concrete container and the sealing layer necessary to ensure fluid-tightness become cold. For protection of the external heat insulating layer there is necessary a second external container in the case of land tanks or a separate hull in the case of ships.